Age-heterogamous partnerships: Prevalence and partner differences by marital status and gender composition

Objective: We examine age heterogamy in the United States and its associations with other partnership characteristics following the nationwide legalization of same-sex marriage in 2015. Methods: We use American Community Survey data for 2017–2021 to examine age gaps in over 3.3 million couples, differentiating by couple gender composition (man-man, man-woman, woman-woman) and marital status (cohabiting, married). We estimate the prevalence of age heterogamy and how it correlates with education, income, and race/ethnicity differences between partners. Results: The prevalence of age heterogamy and its associations with other partner differences vary by couple gender composition and marital status. Man-man couples have higher rates of age heterogamy than man-woman and woman-woman couples; over three in ten man-man couples had age gaps of at least eight years between partners, with no difference by marital status. Age heterogamy was less common among married than cohabiting man-woman couples. For most couple types, educational and income differences between partners were more common among age-heterogamous partnerships. The prevalence of interracial/interethnic partnerships was higher among age-heterogamous married man-man and man-woman couples but not for woman-woman couples. Contribution: Man-man couples have higher rates of age heterogamy, and partner differences related to education, income, and race/ethnicity are tied to age heterogamy for man-man couples more strongly than for other couple types. Partnering patterns for man-man couples are distinct from other couple types.